Aircraft usually have several movable control surfaces attached to the trailing edges of a wing that are used to fulfil different functions.
A typical aileron is hingedly attached to a profile of the wing. The aileron is able to be pivotably rotated around a pivot point resulting in positive or negative actuation with regard to the horizontal plane of the wing profile. The kinematic hinge may be located within or out of the profile of the wing. A usual range of angular displacement ±δ is between ±30°.
Other mechanisms, such as the one known as “dropped hinge flap” due to the relatively to the wing profile “dropped hinge” and pivot point, are for example shown in document U.S. Pat. No. 7,520,471 B2 which illustrates the principles underlying the dropped hinge flap in more detail.
Negative angular movement −δ would be desirable to provide a flap with aileron functionality. However, the flap body of a conventional flap may undesirably penetrate into the wing profile when being actuated in a negative angular movement −δ. Thus, with the conventional dropped hinge flap mechanism, additional measures would have to be taken to provide the flap with aileron functionality.
Other approaches to combined flaps and ailerons have been proposed for example in the documents U.S. Pat. No. 4,544,118 A and U.S. Pat. No. 4,763,862 A. In both documents, a flap is pivotably mounted on a roller running chordwise in a roller guide. Thereby, a horizontal translatory movement towards the trailing edge can be achieved, while at the same time being able to independently pivot the flap around the roller. Such mechanisms are generally known as Fowler-type flaps.